Workbench: Add Shadow Focus and change Shadow Orientation

Shadow focus let the user choose how hard are is the shadows transition.
Harder shadow transition can be used for stylistic effects or more uniform
shading.

Make shadow orientation respect the same orientation as the studio light
(view from +Y direction aka. front view). Make the default shadow direction
more similar to the default light position (the default light object, not
the default studio lighting).

release/scripts/startup/bl_ui/space_view3d.py

@@ -4402,6 +4402,7 @@ class VIEW3D_PT_shading_options_shadow(Panel):
         col = layout.column()
         col.prop(scene.display, "light_direction")
         col.prop(scene.display, "shadow_shift")
+        col.prop(scene.display, "shadow_focus")
 
 
 class VIEW3D_PT_shading_options_ssao(Panel):

source/blender/blenkernel/intern/scene.c

@@ -858,8 +858,9 @@ void BKE_scene_init(Scene *sce)
 	BKE_view_layer_add(sce, "View Layer");
 
 	/* SceneDisplay */
-	copy_v3_v3(sce->display.light_direction, (float[3]){-M_SQRT1_3, -M_SQRT1_3, M_SQRT1_3});
-	sce->display.shadow_shift = 0.1;
+	copy_v3_v3(sce->display.light_direction, (float[3]){M_SQRT1_3, M_SQRT1_3, M_SQRT1_3});
+	sce->display.shadow_shift = 0.1f;
+	sce->display.shadow_focus = 0.0f;
 
 	sce->display.matcap_ssao_distance = 0.2f;
 	sce->display.matcap_ssao_attenuation = 1.0f;

source/blender/blenloader/intern/versioning_280.c

@@ -2480,5 +2480,15 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
 				}
 			}
 		}
+
+		/* Change Solid mode shadow orientation. */
+		if (!DNA_struct_elem_find(fd->filesdna, "SceneDisplay", "float", "shadow_focus")) {
+			for (Scene *scene = bmain->scene.first; scene; scene = scene->id.next) {
+				float *dir = scene->display.light_direction;
+				SWAP(float, dir[2], dir[1]);
+				dir[2] = -dir[2];
+				dir[0] = -dir[0];
+			}
+		}
 	}
 }

source/blender/blenloader/intern/versioning_defaults.c

@@ -301,4 +301,8 @@ void BLO_update_defaults_startup_blend(Main *bmain, const char *app_template)
 			}
 		}
 	}
+
+	for (Scene *scene = bmain->scene.first; scene; scene = scene->id.next) {
+		copy_v3_v3(scene->display.light_direction, (float[3]){M_SQRT1_3, M_SQRT1_3, M_SQRT1_3});
+	}
 }

source/blender/draw/engines/workbench/shaders/workbench_deferred_composite_frag.glsl

@@ -16,6 +16,7 @@ uniform vec4 viewvecs[3];
 uniform float shadowMultiplier;
 uniform float lightMultiplier;
 uniform float shadowShift = 0.1;
+uniform float shadowFocus = 1.0;
 
 layout(std140) uniform world_block {
 	WorldData world_data;
@@ -99,7 +100,7 @@ void main()
 	float light_factor = -dot(normal_viewport, world_data.shadow_direction_vs.xyz);
 	/* The step function might be ok for meshes but it's
 	 * clearly not the case for hairs. Do smoothstep in this case. */
-	float shadow_mix = smoothstep(1.0, shadowShift, light_factor);
+	float shadow_mix = smoothstep(shadowFocus, shadowShift, light_factor);
 	shaded_color *= mix(lightMultiplier, shadowMultiplier, shadow_mix);
 #endif
 

source/blender/draw/engines/workbench/workbench_data.c

@@ -161,7 +161,9 @@ void workbench_private_data_get_light_direction(WORKBENCH_PrivateData *wpd, floa
 	DRW_viewport_matrix_get(view_matrix, DRW_MAT_VIEW);
 
 	copy_v3_v3(r_light_direction, scene->display.light_direction);
-	negate_v3(r_light_direction);
+	SWAP(float, r_light_direction[2], r_light_direction[1]);
+	r_light_direction[2] = -r_light_direction[2];
+	r_light_direction[0] = -r_light_direction[0];
 
 	/* Shadow direction. */
 	mul_v3_mat3_m4v3(wd->shadow_direction_vs, view_matrix, r_light_direction);

source/blender/draw/engines/workbench/workbench_deferred.c

@@ -566,7 +566,10 @@ void workbench_deferred_cache_init(WORKBENCH_Data *vedata)
 		workbench_private_data_get_light_direction(wpd, e_data.display.light_direction);
 		studiolight_update_light(wpd, e_data.display.light_direction);
 
-		e_data.display.shadow_shift = scene->display.shadow_shift;
+		float shadow_focus = scene->display.shadow_focus;
+		/* Clamp to avoid overshadowing and shading errors. */
+		CLAMP(shadow_focus, 0.0001f, 0.99999f);
+		shadow_focus = 1.0f - shadow_focus * (1.0f - scene->display.shadow_shift);
 
 		if (SHADOW_ENABLED(wpd)) {
 			psl->composite_pass = DRW_pass_create(
@@ -576,7 +579,8 @@ void workbench_deferred_cache_init(WORKBENCH_Data *vedata)
 			DRW_shgroup_stencil_mask(grp, 0x00);
 			DRW_shgroup_uniform_float_copy(grp, "lightMultiplier", 1.0f);
 			DRW_shgroup_uniform_float(grp, "shadowMultiplier", &wpd->shadow_multiplier, 1);
-			DRW_shgroup_uniform_float(grp, "shadowShift", &scene->display.shadow_shift, 1);
+			DRW_shgroup_uniform_float_copy(grp, "shadowShift", scene->display.shadow_shift);
+			DRW_shgroup_uniform_float_copy(grp, "shadowFocus", shadow_focus);
 			DRW_shgroup_call_add(grp, DRW_cache_fullscreen_quad_get(), NULL);
 
 			/* Stencil Shadow passes. */
@@ -614,7 +618,8 @@ void workbench_deferred_cache_init(WORKBENCH_Data *vedata)
 			workbench_composite_uniforms(wpd, grp);
 			DRW_shgroup_uniform_float(grp, "lightMultiplier", &wpd->shadow_multiplier, 1);
 			DRW_shgroup_uniform_float(grp, "shadowMultiplier", &wpd->shadow_multiplier, 1);
-			DRW_shgroup_uniform_float(grp, "shadowShift", &scene->display.shadow_shift, 1);
+			DRW_shgroup_uniform_float_copy(grp, "shadowShift", scene->display.shadow_shift);
+			DRW_shgroup_uniform_float_copy(grp, "shadowFocus", shadow_focus);
 			DRW_shgroup_call_add(grp, DRW_cache_fullscreen_quad_get(), NULL);
 #endif
 

source/blender/makesdna/DNA_scene_types.h

@@ -1441,13 +1441,12 @@ typedef struct DisplaySafeAreas {
 /* Scene Display - used for store scene specific display settings for the 3d view */
 typedef struct SceneDisplay {
 	float light_direction[3];      /* light direction for shadows/highlight */
-	float shadow_shift;
+	float shadow_shift, shadow_focus;
 
 	/* Settings for Cavity Shader */
 	float matcap_ssao_distance;
 	float matcap_ssao_attenuation;
 	int matcap_ssao_samples;
-	int pad;
 
 	/* OpenGL render engine settings. */
 	View3DShading shading;

source/blender/makesrna/intern/rna_scene.c

@@ -5591,7 +5591,6 @@ static void rna_def_scene_display(BlenderRNA *brna)
 	RNA_def_property_update(prop, NC_SCENE | NA_EDITED, "rna_Scene_set_update");
 
 	prop = RNA_def_property(srna, "shadow_shift", PROP_FLOAT, PROP_ANGLE);
-	RNA_def_property_float_sdna(prop, NULL, "shadow_shift");
 	RNA_def_property_float_default(prop, 0.1);
 	RNA_def_property_ui_text(prop, "Shadow Shift", "Shadow termination angle");
 	RNA_def_property_range(prop, 0.0f, 1.0f);
@@ -5599,6 +5598,14 @@ static void rna_def_scene_display(BlenderRNA *brna)
 	RNA_def_property_clear_flag(prop, PROP_ANIMATABLE);
 	RNA_def_property_update(prop, NC_SCENE | NA_EDITED, "rna_Scene_set_update");
 
+	prop = RNA_def_property(srna, "shadow_focus", PROP_FLOAT, PROP_FACTOR);
+	RNA_def_property_float_default(prop, 0.0);
+	RNA_def_property_ui_text(prop, "Shadow Focus", "Shadow factor hardness");
+	RNA_def_property_range(prop, 0.0f, 1.0f);
+	RNA_def_property_ui_range(prop, 0.0f, 1.0f, 1, 2);
+	RNA_def_property_clear_flag(prop, PROP_ANIMATABLE);
+	RNA_def_property_update(prop, NC_SCENE | NA_EDITED, "rna_Scene_set_update");
+
 	prop = RNA_def_property(srna, "matcap_ssao_distance", PROP_FLOAT, PROP_NONE);
 	RNA_def_property_float_default(prop, 0.2f);
 	RNA_def_property_ui_text(prop, "Distance", "Distance of object that contribute to the Cavity/Edge effect");